Re: GAUDET C trumpet
I almost bought that horn. I missed out, but luckily I found another one on sale from a seller in France
As others have said, the Gaudet line was Courtois's student/intermediate line.
That said, mine plays like a horn costing at least 10 times more (I paid $300 inc. shipping from France). I've played it against a friend's Xeno C, and the Gaudet stands up better to being pushed. On the Xeno, loud = brash, whereas the Gaudet just gets... louder.
Comparisons notwithstanding, as a C trumpet in its own right, I just love the sound it produces. It sings in every register, with a big sound despite only having an ML bore.
When I first picked it up, it had the usual intonation quirks on E, Eb, and G, but I found that changing mouthpieces (and therefore, I guess, gap) has corrected that. My first inclination was to go down to a tighter mouthpiece, but that gave a very brittle tone. The best sound ironically comes with my normal piece, a Blessing 1.5C. Of course, if I can get my hands on a vintage Courtois mouthpiece at some point, I'll try that.
I guess the real question is, what do manufacturers change between pro and student models? And that comes down to economics.
It doesn't make sense to vary the raw materials since they'd get a better deal buying in greater bulk. So probably not much saving there.
Manufactured parts would be made on the same lines, but maybe by less experienced builders? That would reduce the cost of the lower-end models. But they are still people who were working for Courtois, one of the finest brass makers in the world, and they would have been taught by master craftsmen.
The Gaudet only has a 3rd valve ring (which has actually been removed on mine, so I'm going to have to get one put on) and nothing on 1st, so that's another saving.
Where the biggest savings probably came, though, is in time. I suspect tolerances are looser in the student horns, there may be differences in how processes like valve lapping were carried out, the plating is probably thinner, and there was maybe less attention to prep and polishing beforehand. Similarly, QA may have been less stringent than for a pro horn.
This is all conjecture, of course.
But in the end, all horns - pro or student - are hand made, so there's always the chance to get a star for $300 or a dog for $3000.
Is mine worth $300? Definitely. I was lucky. The bell has been repaired at some point, but very professionally. The plate is near perfect, and the compression is tight. I checked valve alignment and it's spot on, which makes me think someone aligned them in the past. Intonation is good and the sound quality is on a par with a good Bb, like you say.
Is yours worth 250 EUR? If it plays well, which it sounds like it does, then who cares what name is stamped on the bell